Chain rubbing front deraileur

veterangaz
veterangaz Posts: 79
edited March 2014 in Workshop
I have tried looking at youtube videos yet still can never seem to fix this. When I am in the biggest chainring and smallest rear sprocket the chain rubs the deraileur. On youtube videos it is simply a case of adjusting the limit screws and they move the cage out slightly, mine doesn't move out or in though when I adjust them and am not sure why, any ideas?

Comments

  • Semantik
    Semantik Posts: 537
    the limit screws don't move the derailleur at all. they just limit its range of movement. it's the cable that moves the derailleur and incorrect tension in the cable is likely to be your problem.
  • veterangaz
    veterangaz Posts: 79
    So do I just release the cable a little more, eg undo it and slide a touch more through?
  • Semantik
    Semantik Posts: 537
    there should be a barrel adjuster on the frame down tube that can be used to adjust the cable tension to the derailleur. Sounds like it needs turning a couple of turns to increase cable tension. Or there could be TOO MUCh tension in the cable,which is stopping the derailleur reaching its full travel. in which case turn the other way.
  • apreading
    apreading Posts: 4,535
    I find that when adjusting the limit screws, you sometimes need to change down and then back up with the shifter to see the effect. My analysis of this is that maybe the limiter is stopping the shifter from pulling more cable before adjusting, so maybe you need to go through this cycle to pull the extra cable now allowed by the increased limit.

    I think the lower adjustment, on the small ring, you see the adjusment of the limiter moving it - this is only for the big ring (and maybe middle if you have one).

Categories